METHOD FOR LIMITING WATER INFLOW IN WELL Russian patent published in 2017 - IPC E21B33/138 E21B43/12 

FIELD: oil-and-gas industry.

SUBSTANCE: invention relates to oil industry, in particular to methods of limitation of water inflow in a well, using water-swellable polymers, and can be used during waterproofing works to limit the inflow of the bottom, edge or injected water penetrating through highly permeable seams or fractures. The method comprises preparation and injection into the perforated interval (to be isolated) of swellable elastomer suspension in the water-soluble polymer solution. Into the perforated interval (to be isolated) 5-15 m³ of 1-1.5% of the water-swellable elastomer suspension in 0.1-0.2% water-soluble polymer solution and 10-25 m³ of water suspension of bentonite with the density 1160- 1320 kg/m³ are consistently and continuously injected. The named injection cycle is repeated from 1 to 5 times depending on the injectivity of the perforated interval. After completion of injection the additional volume of 5-10 m³ of 0.5-0.8% water solution of water-soluble polymer is injected with addition of 0.08-0.16% chromium acetate from the volume of water soluble polymer. The water-soluble polymer is polyacrylamide with the mass fraction of water insoluble residue no more than 0.3%, and the water-swellable elastomer is partially crosslinked polyacrylamide with the mass fraction of the soluble part no more than 5%, the solutions of water-soluble polymer and suspension of bentonite powder are prepared using the water with the density 1090-1180 kg/m³.

EFFECT: invention is featured by improvement of efficiency of the method of limitation of water inflow in the well and prolongation of the effect from its application.

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